Small Engines (Lawn Mowers, etc.): uneven deck cut on Craftsman 3500 series riding mower, blade tips, tire inflation

Question
First noticed that the blades were cutting into the earth, even at level 3 on the blade adjust.  I leveled the deck according to the owners manual.  I readjusted the bogie wheels.Checked tire inflation. However even at level 4 on the deck adjust the cut is OK on the left and right sides, but down the centerline it is high. almost no cut at all.  I changed the blades no improvement.  Any ideas?

Answer
Were there any spacers on the blades?  Are the blade jackhshaft bearings wore?  If you remove the deck, flip it upside down and arrange the blades so the blade tips line up, are the blades the same height?
Send me the mower model number, xxx.xxxxx, so I can look up your deck.
Eric